San Isidro Villa de Allende Wastewater Treatment Plant, Villa de Allende, Mexico

San Isidro Villa de Allende is a municipal wastewater treatment facility located in Villa de Allende, Estado de México, Mexico. The plant serves a small population of 913 residents, reflecting its role in a rural or peri-urban community. It operates under Mexico's national water regulations, which require secondary treatment for discharges into inland waters. The plant provides secondary treatment, a standard biological process that removes organic matter and suspended solids. With a designed capacity of 172.80 m³/day and an actual discharge volume of 86.40 m³/day, the facility operates at about 50% capacity, indicating room for future growth or seasonal variability. As a small-scale plant, it is typical of decentralized wastewater infrastructure in Mexican municipalities. The treated effluent is discharged into local water bodies that eventually drain into the Pacific Ocean via the Balsas River basin. The plant plays a key role in protecting downstream water quality and aquatic ecosystems in the region. Its operation supports public health and environmental sustainability in the Lerma-Chapala watershed.

The plant discharges into the Lerma River basin, which flows into Lake Chapala, Mexico's largest freshwater lake, and eventually to the Pacific Ocean via the Santiago River. The watershed supports diverse aquatic life and is important for irrigation and drinking water. Protecting this system from untreated wastewater is critical for maintaining water quality and ecosystem health.